1. Field of the Invention
This invention relates to a method and apparatus for controlling a drink dispenser. More particularly, this invention relates to a method and apparatus for programming a drink dispenser during a program mode and to dispense beverage as a function of stored volumetric parameter data during a dispense mode.
2. Description of the Prior Art
Drink dispensers have generally taken one of three forms. The first form involves mechanical levers which respond to the presence of a cup under a dispensing valve. For an operator to fill a glass of liquid, the operator places a cup under the dispensing valve thereby depressing the mechanical lever which, in turn, opens the dispensing valve and allows liquid to pour into the cup. In order to fill the cup to the proper level, the operator must devote full attention to the cup. Although the operator could fill one cup with each hand, this type of drink dispenser is very inefficient.
The second form is a portion control which utilizes a spray of liquid being dispensed to complete a link in an electrical circuit between an actuating lever and the liquid flowing through the dispensing valve. A cup is placed under the dispensing valve thereby actuating the actuating lever. As the liquid level in the cup rises, the spray increases. Consequently, the impedance in the electrical circuit decreases allowing greater current to flow through the electrical circuit. When a predetermined level of current is reached, the dispensing valve is shut off. This type of dispenser is described in detail in U.S. Pat. No. 4,641,692 to Bennett.
The third form is a conventional portion control type drink dispenser. The portion control type drink dispenser operates on a timed dispensing cycle which assumes constant fluid flow through the dispensing valve. A known cup size and a known amount of ice in the cup are also assumed. A dispenser timer is triggered by momentary actuation of a push button for a given drink size. The dispensing valve stays open during the dispensing cycle which is timed by the dispenser timer. Therefore, an operator may place a cup under the dispensing valve, press the push button for the desired drink size and attend to other chores while the cup is being filled.
However, many drinks dispensed through this type of dispenser are carbonated. Therefore, an operator may be required to allow the foam on the drink to settle, after it has been initially filled by the dispenser, and then to manually top off the drink. This is inefficient from the standpoint of the operator.
Also, this type of drink dispenser generally utilizes individual trimming potentiometers to vary dispense time for each drink size. Therefore, when this type of drink dispenser is being installed, the trimming potentiometers must all be adjusted to allow the proper volume of liquid to be dispensed for each drink size. Also, re-adjustment is occassionally required to maintain proper operation of the dispenser. A maladjusted dispenser can result, for instance, in "short" timed dispensing cycles which fail to fill the cup all the way. Any re-adjustment also requires adjusting the trimming potentiometers.
Timing correction required during installation or re-adjustment usually involves dumping the partially filled cup content, turning the trimming potentiometer for the drink size being adjusted and re-actuating the push button to see if the desired volume of liquid is dispensed. Typically, adjustments take several iterations before the trimming potentiometers are set properly.
This "trial and error" procedure results in undesirable waste of beverage and time. Adjusting all the liquid dispensers in a restaurant can waste an undesirable amount of time and cause gallons of drinks to be wasted. Therefore, there is a need for a drink dispenser which can be automatically set to dispense the proper volume of liquid while pouring the first drink from the dispenser so that no beverage is wasted.
Additionally, since many carbonated beverages are dispensed through drink dispensers, there is a need for an automatic drink dispenser which fills a cup, allows the foam on the drink to settle, and tops off the drink automatically.